This invention relates generally to crime prevention and detection methods and, more particularly, to a method for chemically labeling and thereby subsequently detecting and identifying stolen articles and the thief thereof by means of a latent color reagent containing as an active ingredient ninhydrin or hydrindantin or a mixture thereof.
Burglaries, robberies and other crimes wherein property is stolen frequently go unsolved because of the inherent difficulties in adequately identifying and tracing the stolen goods as well as difficulties inherent in adequately identifying the thief. With respect to identifying stolen goods, the problem is particularly acute where the goods are fungible or otherwise not readily distinguishable from other similar goods. Money is the foremost example of an article that is not readily identifiable or traceable except by recording of serial numbers. Recording of serial numbers is tedious and impractical for most businesses. Consequently, where money is stolen during a burgarly or robbery, the crime is almost never solved by subsequently identifying money found in the possession of a suspect as the money which was stolen. If such a crime is solved at all, it is typically on the basis of subsequent identification of the criminal by personal recognition of eye witnesses or by conventional forensic science techniques such as fingerprint analysis.
Various devices and methods have been proposed in the past for marking a thief or robber during the commission of his crime. For example, the paten to Howatt, U.S. Pat. No. 1,983,461 teaches the use of a dye-squirting device to be concealed in a bundle of money and discharged by a bank teller or clerk as the money is handed over to a robber. This device has not met with any commercial acceptance because it requires the teller to commit an overt, aggressive act that is likely to antagonize the robber.
Another crime detection system disclosed in U.S. Pat. No. 2,909,767 to Zaltman employs dye-spraying devices which are hidden outside a bank entrance and which are actuated during a robbery by bank employees by means of hidden switches inside the bank. The hidden devices spray the bank robbers with dye as they flee the bank and thereby mark them for later identification. This system has proved impractical because of its complexity and unreliability. Furthermore, it does nothing to mark the stolen money for future identification and tracing.
Another theft detection device disclosed in U.S. Pat. No. 3,730,110 to Peters teaches the use of a hidden dye-spraying device inside a cash register. The device is normally deactuated at the beginning of each work day by persons having authorized acess to the cash register and having knowledge of the theft protection system. Unauthorized handling of the cash register or its contents by persons unaware of the device, however, triggers the device and results in permanent staining of the money in the cash register. Although this device may be of some use in deterring a theft, it offers little help in subsequently identifying the thief or the stolen goods because the plainly visible dye on the stolen goods will cause the thief to conceal the money or even discard it to rid himself of the incriminating evidence.
Accordingly, it is an object of the present invention to provide a method for reliably labeling goods at such time as they may be stolen by theft or robbery. It is a further object of this invention to provide a method which chemically labels the goods in a manner imperceptible to the thief and which therefore does not prompt the thief to conceal the goods or prematurely discard or otherwise dispose of them in order to rid himself of the obviously incriminating evidence.
It is also an object of the present invention to provide a method of chemically labeling the person of the criminal during the course of his crime without antagonizing or arousing the suspicions of the criminal. In this regard, it is a further object to provide a method for chemically labeling the criminal in a manner which is not apparent during the course of the crime, but which becomes readily apparent to even a casual observer within a short time after the crime has been committed.
It is yet another object of the present invention to provide a method which similarly labels and identifies the clothing worn by the criminal during the commission of his crime.